1. Field of the Invention
The present invention relates to an optical printer having a vibration detector, and more particularly to an optical printer to be used in a portable electronic still camera and so forth.
2. Description of the Related Art
As to an optical printer, it is known that printing is performed with a print head scanning a recording paper. Meanwhile, an electronic still camera with a printer is known. Such an electronic still camera has a built-in optical printer superior in portability, as disclosed in Japanese Patent Laid-Open Publication No. 11-252491. A print head of an exposure type is provided with a red-light emitting portion which has a line shape so as to extend in a main-scanning direction. A green-light emitting portion and a blue-light emitting portion respectively having a line shape are arranged in a sub-scanning direction of the red-light emitting portion. Line-shaped recording light, intensity of which is modulated based on image data, is generated relative to each color of red, green and blue. After exposure of one line has been completed, the print head is moved by one line in the sub-scanning direction in order to expose the next line.
The above-mentioned optical printer, however, has a shortcoming that unevenness of print occurs due to a swing of the print head. The swing of the print head is caused by vibration applied at the time of printing. Especially, in case the vibration is applied in a sub-scanning direction which is a moving direction of the print head, exposure portions of the respective colors are shifted. Hence, the unevenness of print is likely to be caused. This phenomenon remarkably appears in a portable apparatus, for example, in an electronic still camera with a printer, since such an apparatus is frequently carried with a user. In the optical printer, exposure is performed in a state that the print head does not contact with a film surface. Sometimes the print head contacts with the film surface due to the vibration so that the film surface is likely to be damaged.
In view of the foregoing, it is a primary object of the present invention to provide an optical printer in which unevenness of print is prevented from being caused due to vibration.
It is a second object of the present invention to provide an optical printer in which printing is easily performed without an extra operation.
In order to achieve the above and other objects, the optical printer according to the present invention comprises a vibration detector and a print controller. When the vibration detector detects the vibration exceeding a prescribed level, the print controller interrupts a printing operation of the printer.
In a preferred embodiment, a print head is adapted to be moved, performing the printing operation one line by one line. Even if the vibration detector detects the vibration exceeding the prescribed level, the print controller suspends to interrupt the printing operation until completion of one-line printing.
After interrupting the printing operation, the print controller resumes the printing operation when the vibration detector detects the vibration falling below the prescribed level.
It is preferable that the vibration detector detects the vibration relative to a moving direction of the print head.
According to the present invention, unevenness of print may be prevented from occurring under a condition that the vibration is applied during the printing operation. In addition, the printing operation is automatically resumed after interruption thereof. Thus, once an instruction for printing is given, it is unnecessary to give the instruction for printing again. The printing operation may be easily performed without an extra instruction.